For the pilau, heat a deep frying pan or saucepan until medium hot, add the oil and butter and gently cook the onion, garlic and lemongrass for about two minutes, or until just softened.
Add the rice and cook for one minute, stirring all the time, then add the stock and bring to a simmer.
Reduce the heat and cover with a lid, then simmer gently for 15 minutes or until the stock is absorbed and the rice is tender.
Stir in the lime zest, juice and coriander and season to taste with salt and freshly ground black pepper.
Meanwhile, rub the steaks with the vegetable oil. Mix together the potato flour and star anise and thoroughly dust the steaks, pressing the flour onto the meat to completely cover it.
Heat a frying pan until hot, add the olive oil, then fry the steaks for 2-3 minutes on each side. Remove the steaks from the pan and set aside to rest for 2-3 minutes.
Place the rice wine vinegar and caster sugar in a separate pan and bring to a simmer. Add the soy, chilli and ginger and simmer for 4-5 minutes, or until the sauce is thick and slightly sticky.
To serve, spoon some pilau rice onto each plate. Carve the steak into thick slices, place over the pilau and then pour the sticky chilli sauce over the steak.